Draw labelled graphs to show how electrical resistance varies with temperature for :
(i) a metallic wire.
(ii) a piece of carbon

Explanation

To solve the question of how electrical resistance varies with temperature for a metallic wire and a piece of carbon, we will draw two labeled graphs and explain the characteristics of each.

### Step-by-Step Solution:

#### (i) Graph for a Metallic Wire:

1. **Understanding Resistance in Metals**:
- The resistance of metallic wires increases with an increase in temperature. This is due to increased vibrations of the metal atoms, which impedes the flow of electrons.
...